Micrometer-gage.



G. A. HIRTH. MICROMETBR GAGE. APPLICATION IILED MAYIO, 1907.

Patented Jan. 7, 1913.

2 SHBETS-SHBET 1.

' C. A. HIRTH. MIGROMETER GAGE. APPLIOATIQR' rmin In 10, 1901.

1,049,86QQ v Patnted Jan. 7, 1913.

2 SHEETS-SHEET 2-.

W3. Fig.6;

;- To all whom it may concern:

STATES TENT O CE. j

5 ALBERT mark, or CANNSTADT, sru'rream'; GERMANY.

.. v MTCROMETEB-GA'GEf 'Be it known that I, CARL ALBERT- HIRTH,

a subject of the German Emperor, residing proved construction for the at Cannstadt, Stuttgart, in the German Empire, have invented a new and useful I mprovement in Micrometer- Gages, of whlch the following is a specification. v D

Y The invention relates to improvements 1n micrometer gages and particularly to gages having a lever for indicating the measure ments, the object being to provide an impurpose of increasing the limit of accurac With this object the device consists in it. main features of a'rec'essed lever havingfwo y a arms of unequal length and loaded spring; the shorter arm of the lever is acted upon by one part of the object to be measured when another part of said object is applied to a fixed cont-act piece; and the longer arm of'the lever takes the form of a pointer.

This construction enables the ratio of am-.

.plification' of the lever arms, z. e. the limit of accuracy to be carried to any desired extent without the necessity for using a double -lever transmission. The lever is preferably mounted on knife edges both at its fixed point of rotation or fulcrum and at the movable oint where pressure is applied; the said edges are relatively adjustable and fit on opposite sides into recesses in the lever and a short distance apart, the lever being Plt .sed against the "knife edges by a spring or any other convenient means.

In the accompanying drawings :Figure 1 shows in longitudinal section one convenient form of gage according to this-invention. Fig. 2 is a longitudinal section of part of a modified construction. Fig. 3 is a section taken on the line 3-3 of Fig. 1.

Figs. 4 and 5 are respectively front and side views of a detail. Fig. 6 is a sectionof the modifiedconstruction shown in Fig. '2. Fig. 7 is an enlarged View of part of the structure shown in Fig. 1, and Figs. 8, 9 and 10 illustrate a'further modification in vertical.

section, elevation and plan respectively.

The indicating lever a is contained within a casing 0! provided with cover plates 6 c,

and 'carries at one end a pointer e which is -arranged to move over ascale f and is formed with two lugs go one on either side I 5 which act as lateral guides. A longitudinal 5 recess or groove 0 is provided on one side of I Specification of LettersPatentL Patented Jail- 7, 1913. Application filed May 10, 1907. Serial in. 372,947.

the lever a anda transverse recess or groove 9 is provided on the opposite side; the said recesses intersecting. In the longitudinal recess o is a slide u having a transverse groove m which a knife edged fulcrum g is located. The fulcrum g is mounted so as to be slidable in a supportin member 2' suitably secured to one wall 0 the casing. On

the opposite side of the levera a pin m is slidably mounted in a guide is suitably secured to the wall of the casing. The pin m, has a head It formed with two knife edge portions with a space between them as,

edges of the pin m. A shoulder is formed between the head hand the pin m and a spring n, which is interposed between the casing and the fulcrum side of the lever, normally forces the pin m through its guide 70 until the shoulder vabuts against this guide. It will be seen that when pressure is applied to the pin on the lever a will turn about its fulcrum 9 against the action of the spring n and the degree of displacement will be indicated by the pointer e on the scale f. The casingjis mounted upon a base plate or support Z whichcarries fixed stops 7 s and the article to be measured or gaged (suchfor example the ring R) is made to contact with the two stops r s and the pin m. The size of the article can then be judged by comparing the deviation of the pointer with that produced by an article of standard dimensions.

The points where the knife edges make contact in their respective recesses lie on the same longitudinal plane of the lever and the relative distance between the two points is reduced to a minimum, that is to say, the two points almost coincide with each other so that the deflection of the lever may be increased to any convenient maximum extent without as hitherto necessitating double transmission by providing a second lever influencing the first. i

Fig. 2 illustrates a modification of the gage, in which the lever a is mounted on knife edges bothat the fulcrum and the point of application of pressure. This construction possesses the advantage in that the ,lever a turns uniformly on the knife edge 9. Since the obliquity'of the lever a during its movement causes a relative (118 lacement of the two points of action on the central line of axis of the lever, one of these two points must be rendered adjustable within narrow limits. In the.modification illustratedin Fig. 1, this is accomplished by fitting the lever a with the movable strip w-which passes between the two .knife edged portions of the head k-to form a movable abutment for the edge 9 and containing a recess for the latter extending to the central line or axis of the lever. The adjustable strip u is-not secured to the part a so that a slight displacement of the said strip with relation to the lever on occurs automatically when the lever is moved into an inclined or slanting position in measuring, the edge 71. in that event moving in .a straight line at right angles to the axis of the lever a. A further and positive adj'zi lstment may be attained as shown ineither ig. 1 or in Fig. 2. As shown in Fig. 1 the knife edge 9 is displaced in a slide j in the.

guide block i, by means of a micromet screw w. The strip a is moved at the; same time owing to its. being engaged "by the knife-edge g. This adjustment, however, is quite independent of the automatic adjustment of the strip u described above. The strip u enables the sensitiveness of the lever a to be adjusted by altering the relative distance between the knife edges. Since the strip 16 forms a firm abutment when the knife edges 9 h are within a fraction of a millimeter apart, the adjustment can be effected within wide limits. In the construction illustrated in Figs. 2 and 6, the regulation is effected by displacement of the strip u by a micrometer screw 3 arranged on the lever a, in which latter case the knife edge 9 must be mounted in its carrier or guide block i in such a manner as to allow it to oscillate, as shown in Fig. 2, in order to enable the two knife edges 9 h to undergo ,felative displacement during the swing of the lever a. To enable the pointer to be set to zero under varying adjustments of the gage, a micrometer screw 4 (Fig. 1) is provided above the slide j of the knife edge which screw v acts in opposition to the spring 91. so that the slide accurately follows the vertical movement of the micrometer screw v.

The further modified form illustrated in Figs. 8, 9 and 10, can be quickly and easily adjusted for measuring articles of different sizes. The pointer e of the lever is here mounted at right angles with the actual lever a, and the casing d of the gage lever is made cylindrical. The casing can be adjusted by hand in the bore of a holder Z until the stop or pin m comes in contact with the article to be measured. The casing is then fixed in position by means of the clamping screw 9. The accurate adjustment of the gage lever to the zero point is efiected by means of the micrometer screw 3, which acts on a female threaded attachment 4 of the holder 1. The'attachment 4 and micrometer screw 3 are forced toward the left by a spring 5, so that the shoulder 6 of the micrometer screw always rests against the wall of the frame.

The third stop 1- is adjust-able for various dimensions of the article tobe measured. For rings it is preferred to have the stop 1' movable on. a plane 7 sloping toward the stop .9, this arrangement enabling the rings to be always supported in the center, whatever their diameter. The stop 0 is mounted on a slide 8 which can be set by a scale 9, and fastened in position by a clamping screw 10.

What I claim is 1. In a micrometer gage the combination of support, a lever having a plurality of arms of unequal length one of said arms forming a pointer, a fulcrum mounted on said support and having a knife-edge contact with said lever a pin movably mounted in said support,and having a knife-edge contact with said lever, one of said knife edges being forked and making contactwith the lever on each side of the other knife edge whereby almost coincide, said pin being adapted to impart motion to said lever and means cooperating with the fulcrum and actuating pin whereby the pointer is normally held in a predetermined position.

2'. In a micrometer gage the combination of a support, a lever having a plurality of arms of unequal length one of said arms forming a pointer, a fulcrum mounted on said support and having a knife-edge contact with one side of said lever, a pin movably mounted in said support and having a knife-edge contact with the opposite side of said lever, one of said knife edges being forked and making contact with the lever on each side of the other knife edge whereby the points of contact may almost coincide, said pin being adapted to impart motion to said lever and meanscoiiperating with the fulcrum and actuating pin whereby the pointer is normally held in a predetermined position.

a 3. In a micrometer gage the combination of a support, a lever provided on its opposite sides with'recesses, an adjustable knifeedge fulcrum entering a recess on one side of the lever, an actuating pin having a knife edge entering a recess on the opposite side of the lever and adapted to impart motion to the lever, one of said knife edges being forked and making contact with its recess on each side of the other knife edge whereby the point of contact may almost coincide, a pointer forming part of said lever, and

the points of contact may igneous cooperating 1 with the fulcrum and Biactuati pin whereby the pointer is normally h d in a predetermined position.

- one end and being movably mounted upon the support for applyin pressure to one side of said lever being a apted at the other end to contact'with the article to be measured, .one of said knife edges being forked and making contact with-its recess on each side of the other knife edge whereby the points of contact may almost coincide, means cooperating with the fulcrum and the actuating pin whereby the lever is supported in its normal position, meansfor ad usting the relative positions of the pin and the portionof thefulcrum about which the lever rocks, and stops carried by the support and against which the articles to be measured contact; substantially as described. 7

5. In a micrometer gage the combination of a support, a lever having a plurality of arms of unequal len h one of said arms forming a pointer an Q said lever being provided with a lurality of recesses, a knifeedge fulcrum or the lever said fulcrum being located in one of said recesses and mounted upon the support, a pin having a knife edge at one end and movably mounted u on the support and being adapted to app y pressure to said lever said pin being adapted at the other end to contact with the articles to be measured and being in engagement with another of said recesses, and one of said knife edges being forked and making contact with its recess on each side of the other knife edge whereby thepoints of contact may almost coincide, means cooperating with the fulcrum and the actuating pin whereby the lever is supported in its normal position, and stops carried by the support pand against which a the articles to be measured contact; substantially as described.

6. In a micrometer gage the combination of a su port,,a lever having a plurality of arms 0 unequal length one of said arms forming a pointer and said lever being prov vided with a plurality of recesses, a knifeedge fulcrum for the lever said fulcrum being located in one of said recesses and mounted on the support, apin having a knife edge at one-end for applying pressure to said lever and being adapted at the other end to contact with the article to be measured, said pin being also in engagement with another of the sa d recesses and movably mounted on the support, and one of said knife edges being forked and making contact with its recess on each side of the other knife edge whereby the points of con- I tact may'almost coincide, means cooperating with the fulcrum and the actuating pin whereby the lever is en ported in its normal pos tion, means for a ]usting the relative ositions of the pin and the portion of the lcrum about which the lever rocks, and stops mounted upon the support and against WhlCh the articles to be measured contact; substantially as described.

7. In a micrometer gage the combination of a support, a lever having a plurality of arms of unequal length one of said arms forming a pointer and said lever being provided on its opposite sides with recesses, a

knife-edge fulcrum bearing against one side ofthe lever said fulcrum being located in one of said recesses and mounted upon the support, a pin having a knife edge atone end and being movably mounted upon the support and adapted at the other end to contact with the article to be measured and being also adapted to apply pressure to the opposite side of saidlever said pin being in engagement with another of the recesses in the lever, and one of said knife edges being forked and making contact with its recess at each side of the other knife edge whereby the points of contact may almost coincide, means cooperating with thefulcrum and the actuating pin'whereby the lever is supported in its normal position, and stops mounted upon the support and against which the articles to be measured contact; substantially as described.

8. In a micrometer gage the combination of a support, a lever having a plurality of arms of unequal length one of said arms forming a 'pointer and said lever being provided on its opposite sides with recesses, a knife-edge fulcrum bearing against one side of the lever said fulcrum being located in one of said. recesses "and mounted upon the support, a pin having a forked knife edge at one end for applying pressure to the opposite side of said lever said pin being adapted at its other end to contact with the article to be measured and being movably mounted upon the support and in engagement with two parts of another recess and at both sides of the other knife edge, means cooperating with the fulcrum and the actuating pin whereby the lever is supported in its normal'posi-tion, means for adjusting the relative positions of the pin and the portion of the fulcrum about which the lever rocks, and stops mounted upon the support and against which the articles to be measured contact; substantially as described.

9. In a micrometer gage the combination of asupport, a recessedlever having a plu rality of arms of unequal length one of said arms forming a pointer, a fulcrum for said lever located in said recess and mounted upon the support, a pin mounted upon the support and for applying pressure to one 10. In a micrometer gage the combination.

of a support; a recessed lever having a plurality of arms of unequal length one of said arms forming a pointer; knife edges carried by. the support and forming a fulcrum and supporting pin respectively for said lever, the knife edge of the said supporting pin being in two parts; a strip longitudinally slidable on said lever bet-ween the two parts of the knife edges of the said supporting pin whereby the position of the fulcrum may be adjusted; means for moving said strip; means cooperating with the fulcrum and the actuating pin whereby the lever is supported in its normal position;,and stops mounted upon the support and against which the articles to be measured contact.

11. In a micrometer gage the combination p of a support; a lever having a plurality of arms of unequal length one of said arms forming a pointer and said lever being provided with a plurality of recesses; a knife edged fulcrum for the lever, said fulcrum being mounted upon the support and located in one of said recesses; a knife-edged supporting pin mounted upon the support and Y for applying pressure to said lever, the

knife-edge of the said pin being in two parts that engage with one of the said recesses; a strip longitudinally slidable on said lever between the two parts of the said knifeedge whereby the position of the fulcrum maybe adjusted; means for moving said strlp; means cooperating with the fulcrum and the supporting pin whereby the lever is supported in its normal position; and stops mounted upon the support= and against which the articles to be measured contact.

12. In a micrometer gage the combination of a support; a leverhaving a plurality of arms of unequal length one of said arms forming a pointer and said lever being pro- 7 witnesses.

vided on its opposite sides with recesses; a knife-edged fulcrum bearin against one side of the lever said fulcrumIming mounted upon the support and located in one of said recesses; a knife-edged supporting pin mounted upon the support and for applying pressure to the opposite side 'of said lever, the knifeedge of the said pin being in two parts that engage with one of said recesses; a strip longitudinally slidable on said lever between the two arts of the said knife edge whereby the position of the fulcrum may be adjusted; means for moving said strip; means cooperating with the fulcrum and the supporting pin whereby the lever is supported in its normal position; and stops mounted upon the support and against which thearticles to be measured contact.

13. In a micrometer gage the combination of a support; a lever having a plurality of arms. of unequal length one of said arms forming a pointer and said lever being provided on one side with a longitudinal recess and on the opposite side with a transverse recess; a knife-edged fulcrum bearing against one side of the lever said fulcrum being mounted upon the support and located in the longitudinal recess; a knife-edged supporting pin mounted upon the support and adaptedto apply pressure to the opposite side of said lever, the knife edge of the said pin being in two parts that engage with the transverse recess; a strip longitudinally slidable on said lever in the longitudinal recess and between the two parts of the knife edge of the said supporting pin whereby the position of the fulcrum may be adjusted; means for moving said strip; means cooperating with the fulcrum and the supporting pin whereby the lever is supported in its normal position; and stops mounted upon the support and against which the articles to be measured contact. I

In testimony whereof I have hereunto set my hand in the presence of two subscribing CARL ALBERT HIRTH.

Witnesses:

ERNEST ENTENMANN, HNY. H. MORGAN. 

